1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME LIBRARY COMPONENTS --
5 -- S Y S T E M . C O M P A R E _ A R R A Y _ U N S I G N E D _ 8 --
9 -- Copyright (C) 2002-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 pragma Warnings
(Off
);
38 with System
.Address_Operations
; use System
.Address_Operations
;
40 with Ada
.Unchecked_Conversion
;
42 package body System
.Compare_Array_Unsigned_8
is
44 type Word
is mod 2 ** 32;
45 -- Used to process operands by words
47 type Big_Words
is array (Natural) of Word
;
48 type Big_Words_Ptr
is access Big_Words
;
49 -- Array type used to access by words
51 type Byte
is mod 2 ** 8;
52 -- Used to process operands by bytes
54 type Big_Bytes
is array (Natural) of Byte
;
55 type Big_Bytes_Ptr
is access Big_Bytes
;
56 -- Array type used to access by bytes
58 function To_Big_Words
is new
59 Ada
.Unchecked_Conversion
(System
.Address
, Big_Words_Ptr
);
61 function To_Big_Bytes
is new
62 Ada
.Unchecked_Conversion
(System
.Address
, Big_Bytes_Ptr
);
64 ----------------------
65 -- Compare_Array_U8 --
66 ----------------------
68 function Compare_Array_U8
69 (Left
: System
.Address
;
70 Right
: System
.Address
;
72 Right_Len
: Natural) return Integer
74 Compare_Len
: constant Natural := Natural'Min (Left_Len
, Right_Len
);
77 -- If operands are non-aligned, or length is too short, go by bytes
79 if (ModA
(OrA
(Left
, Right
), 4) /= 0) or else Compare_Len
< 4 then
80 return Compare_Array_U8_Unaligned
(Left
, Right
, Left_Len
, Right_Len
);
83 -- Here we can go by words
86 LeftP
: constant Big_Words_Ptr
:=
88 RightP
: constant Big_Words_Ptr
:=
90 Words_To_Compare
: constant Natural := Compare_Len
/ 4;
91 Bytes_Compared_As_Words
: constant Natural := Words_To_Compare
* 4;
94 for J
in 0 .. Words_To_Compare
- 1 loop
95 if LeftP
(J
) /= RightP
(J
) then
96 return Compare_Array_U8_Unaligned
97 (AddA
(Left
, Address
(4 * J
)),
98 AddA
(Right
, Address
(4 * J
)),
103 return Compare_Array_U8_Unaligned
104 (AddA
(Left
, Address
(Bytes_Compared_As_Words
)),
105 AddA
(Right
, Address
(Bytes_Compared_As_Words
)),
106 Left_Len
- Bytes_Compared_As_Words
,
107 Right_Len
- Bytes_Compared_As_Words
);
109 end Compare_Array_U8
;
111 --------------------------------
112 -- Compare_Array_U8_Unaligned --
113 --------------------------------
115 function Compare_Array_U8_Unaligned
116 (Left
: System
.Address
;
117 Right
: System
.Address
;
119 Right_Len
: Natural) return Integer
121 Compare_Len
: constant Natural := Natural'Min (Left_Len
, Right_Len
);
123 LeftP
: constant Big_Bytes_Ptr
:= To_Big_Bytes
(Left
);
124 RightP
: constant Big_Bytes_Ptr
:= To_Big_Bytes
(Right
);
127 for J
in 0 .. Compare_Len
- 1 loop
128 if LeftP
(J
) /= RightP
(J
) then
129 if LeftP
(J
) > RightP
(J
) then
137 if Left_Len
= Right_Len
then
139 elsif Left_Len
> Right_Len
then
144 end Compare_Array_U8_Unaligned
;
146 end System
.Compare_Array_Unsigned_8
;